call defx#custom#column('mark', {
    \ 'readonly_icon': '✗',
    \ 'selected_icon': '✓',
    \ })
call defx#custom#column('icon', {
    \ 'directory_icon': '▷',
    \ 'opened_icon': '▽',
    \ 'root_icon': ' ',
    \ })
call defx#custom#column('filename', {
    \ 'max_width': 1000,
    \ })
